Environmentally protected electronic network structure and housing combination

Abstract

To provide for simplified and less expensive manufacture without extensive insulation of internal components of a control system with respect to the housing, particularly for electronic ignition and fuel injection control systems, digital and other automotive control electronic systems and the like, a housing (1) of insulating plastic material has a connecting portion (2, 3) integrally formed therewith, which further include, integrally formed therewith, holding and engagement catches and slits (13, 15, 17-23; 62, 69) for a printed circuit board (41) carrying electronic network elements (42) such as transistors, capacitors, resistors, in integrated circuit form, or as discrete elements; and further a cooling device (24, 25; 56; 64; 73) in heat-conductive relationship to a power stage (43; 54; 65; 74) to dissipate heat generated within the power stage, and to transfer the heat over a large area surface connection either to a structural component carrying the entire control unit and/or to a sheet metal cover (49) snapped and crimped over the plastic housing (1) and, in sealed relation, closing off the entire structural unit.

We claim: 
     
       1. Environmentally protected electronic network structure, particularly a control system for automotive vehicles, including a printed circuit board (41) and electrical and electronic circuit elements (42, 43, 65), at least some of which (43, 65) require cooling, having a housing (1) retaining said printed circuit board;   a cover (49) closing off the housing,   the electrical and electronic circuit elements being supported on the printed circuit board;   a heat conducting element (24, 25; 73, 75) located in thermal transfer relation with respect to said at least some circuit elements requiring cooling to conduct heat therefrom;   and an externally accessible multi-terminal connection socket (2) to provide externally accessible electrical terminals,   wherein the housing comprises a unitary pan or tub-shaped element (1) of an electrically insulating plastic material;   said printed circuit board (41) having a unitary projecting portion forming a projecting contact terminal strip (47);   said housing being formed with a slit (3) through which said projecting terminal portion extends, and further being formed with a plug receiving portion externally of the slit and adjacent the projecting portion (47) of the printed circuit board, with clearance, to permit engagement with a plug connector for the terminals of the terminal strip on the printed circuit board;   said unitary plastic element being further formed with internal locating means for positioning and holding the printed circuit board (41) therein;   being additionally formed with an internal attachment means (23, 62, 69) for attachment, in heat transfer relation, of said heat conducting element (24, 25; 73, 75);   and being additionally formed with external attachment means (13, 15) for attachment of the housing to a support structure on the vehicle;   and wherein said cover (49) comprises a metal lid secured to said housing element (1) and closing off the pan or tub-shaped element, while providing for radiation of heat generated by the electrical and electronic elements positioned within the housing.     
     
     
       2. Structure according to claim 1, wherein the plug receiving portion is a rim or boot (5) extending over the slit and surrounding the projecting portion (47) of the printed circuit board, with clearance. 
     
     
       3. Structure according to claim 1, wherein said internal locating means comprises abutment projections (21) formed in the housing for positioning of the printed circuit board; and holding means (21) comprising internally projecting resiliently deflectable snap-over projections, positioned for cooperation with said abutment means (18, 19) and snapping over the printed circuit board (41).   
     
     
       4. Structure according to claim 1, wherein said attachment means (23; 62; 69) comprises attachment eyes positioned in the housing in engagement with said cooling element (24; 25; 73, 75). 
     
     
       5. Structure according to claim 1, wherein said heat conducting element comprises a metal element connected in heat transfer relationship with said cover lid (49) while being electrically insulated therefrom; and wherein an electrical circuit element (74) requiring cooling is directly connected to said metal element.   
     
     
       6. Structure according to claim 5, wherein the metal element (64) is further extended and secured to an attachment eye adapted for attachment to the support structure of the vehicle for direct heat transfer to said support structure of the vehicle. 
     
     
       7. Structure according to claim 6, wherein said attachment eye is directly connected to the attachment means of said housing. 
     
     
       8. Structure according to claim 1, wherein the heat conducting element comprises a two-part structural element (24, 25). 
     
     
       9. Structure according to claim 8, further including an insulating element (27) positioned between the two parts of the heat conducting element. 
     
     
       10. Structure according to claim 9, wherein one of the parts (25) of the heat conducting element includes a connecting terminal lug (37), positioned to extend outside of said housing (1) and forming part of the external attachment means for the housing. 
     
     
       11. Structure according to claim 10, further including at least one attachment lug (51) formed on the cover lid (49) and contiguously positioned over the lug (37) which is a component of the part (25) of the heat conducting element extending externally of the housing. 
     
     
       12. Structure according to claim 1, wherein the housing (1) is formed with recesses (53); and the cover lid (49) is formed with attachment lugs (52) fitting into said recesses.   
     
     
       13. Structure according to claim 1, wherein the housing (1) is formed with a circumferential groove (7); the cover lid (49) has portions seated in the groove;   and a sealing means (50) is provided sealing the edge of the cover lid in the groove and against the housing.   
     
     
       14. Structure according to claim 13, wherein the groove (7) is formed as a recess located in the region of the connecting socket (23) and extends in form of a circumferential groove (8) extending around the remainder of the housing element. 
     
     
       15. Structure according to claim 1, wherein at least a part of the heat conducting element (25; 56) is directly secured to the cover lid (49) for direct heat transfer thereto.